The purpose of this Core is to provide a centralized facility to rapidly evaluate the potential role of identified genes in pediatric cancer, using primary clinical samples and established pediatric cancer cell lines. The Core laboratory will investigate the level of expression of candidate genes by either semiquantitative RT-PCR or Northern blot analysis using probes and sequences provided by the primary investigators. In addition, detailed evaluations of the presence of mutations in candidate genes will be performed. These studies will involve evaluations for rearrangements, deletions, and point mutations using standard methodologies. The centralization of these activities will allow for an efficient utilization of available clinical material and will ensure accurate results free from potential contaminations from cloned sequences in the primary investigator's laboratory. In addition, the availability of detailed clinical information on the primary patients will allow for the rapid assessment of the clinical relevance of interesting findings. This Core will also aid in the evaluation and characterization of neoplastic growths identified in the murine transgenic and knockout/knockin strains generated.